The invention relates to improvements in devices for separably connecting one or more conductors to a terminal, such as the post of a rechargeable accumulator or battery in a motor vehicle. More particularly, the invention relates to improvements in connecting devices (hereinafter called connectors) of the type wherein a substantially cylindrical or slightly conical terminal (hereinafter called post) can be engaged by portions of two clamping jaws which are movable relative to each other to thereby increase or reduce and, when necessary, terminate frictional engagement between the post and the jaws.
It is well known to utilize a connector with two jaws which can form-lockingly engage and frictionally adhere to the post of a battery under the hood of a motor vehicle. The arrangement is normally such that the jaws have integral first end portions, second end portions which are separated from each other by a gap, and median portions which jointly define an opening for the post of a battery or the like. The second end portions can be moved toward each other by a bolt-and-nut fastener, which extends at right angles to the axis of the opening, to thereby reduce the width of the gap and hence the size of the opening for the post. As a rule, the width of the slot is less than the diameter of the opening. The head of the bolt engages the exposed side surface of the second end portion of one jaw, and the shank of the bolt extends through untapped holes in the second end portions of both jaws to mate with a nut at the outer side of the second end portion of the other jaw. The jaws are elastically deformable so that they tend to move their second end portions away from each other, i.e., they tend to increase the width of the gap, so that the connector can be readily slipped off the post upon rotation of the bolt in a direction to permit movement of the second end portions away from each other. A drawback of such connectors is that the nut must be held against rotation while the head of the bolt is rotated in a direction to move the second end portions of the jaws toward each other or to permit movement of the second end portions away from one another. This renders the just described connector unsuitable for manipulation by an automaton (robot). Moreover, the head of the bolt and the nut occupy a substantial amount of space at the exposed sides of the second end portions of jaws. Therefore, it is difficult to provide room for attachment of one or more additional electric cables or other conductors, e.g., to supply electrical energy to various electronic components of a motor vehicle. As a rule, the connector must be dimensioned and configurated in such a way that it does not extend laterally beyond the outline of the battery; this renders it possible to apply a customary cover or cap which overlies the battery in a motor vehicle.
Published German patent application No. 35 31 014 of Welcker discloses a connector wherein the second end portions of the jaws are integral with each other and define a portion of a tapped bore which is parallel to the axis of the opening for the battery post. The tapped bore can receive a screw which serves to displace an insert bounding a portion of the opening for the post so that the insert bears against the post in the opening as long as the screw is properly received in the tapped bore.
A drawback of the connector of Welcker is that the jaws are not elastically deformable and, therefore, only a relatively small portion of the peripheral surface of the post in the opening is engaged by the jaws. A further relatively small portion of the post is engaged by the insert. Mere partial engagement between the peripheral surface of the post on the one hand and the jaws and the insert on the other hand is undesirable, particularly in connection with the posts of batteries in motor vehicles, because repeated and practically continuous vibration of the battery, when the engine is on, is likely to loosen the connector after a relatively short period of use. The establishment of a highly pronounced clamping force is to no avail; in addition, this can result in undesirable permanent deformation of the relatively soft battery post.
French Pat. No. 1.091.782 to Quentin discloses a connector which is similar to the connector of Welcker, except that the insert is integrally connected to the second end portion of one of the jaws by a flexible web so that the insert can change its position relative to the jaws and relative to the battery post in the opening between the jaws when the screw (which has a conical shank) is driven home. The drawbacks of the connector of Ouentin are the same as those of the connector which is disclosed by Welcker.
British Pat. No. 882,205 to Renault describes a connector which is a modified version of the connector of Ouentin. The connector of Renault does not employ a screw or bolt but rather a rotary shaft with radially extending lobes which can dislodge a blade so that the latter engages a portion of the battery post in the opening between the median portions of the jaws. The jaws are not movable relative to each other.